The purpose of this project is to investigate, by nuclear magnetic resonance, phospholipid and energy metabolism in rat and human brain as a function of normal aging, as well as in human Alzheimer's disease, and in a rat central hypocholinergic model of Alzheimer's disease. These studies are designed to determine what, if any, brain metabolic changes are seen with normal aging, whether similar or different metabolic changes are seen in Alzheimer's disease and in a rat model of Alzheimer's disease; and whether a new class of drugs known as nootropic drugs or cognition activators can favorably alter abnormal brain metabolism.